1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Remote Processor Framework Elf loader
4 *
5 * Copyright (C) 2011 Texas Instruments, Inc.
6 * Copyright (C) 2011 Google, Inc.
7 *
8 * Ohad Ben-Cohen <ohad@wizery.com>
9 * Brian Swetland <swetland@google.com>
10 * Mark Grosen <mgrosen@ti.com>
11 * Fernando Guzman Lugo <fernando.lugo@ti.com>
12 * Suman Anna <s-anna@ti.com>
13 * Robert Tivy <rtivy@ti.com>
14 * Armando Uribe De Leon <x0095078@ti.com>
15 * Sjur Brændeland <sjur.brandeland@stericsson.com>
16 */
17
18 #define pr_fmt(fmt) "%s: " fmt, __func__
19
20 #include <linux/module.h>
21 #include <linux/firmware.h>
22 #include <linux/remoteproc.h>
23 #include <linux/elf.h>
24
25 #include "remoteproc_internal.h"
26
27 /**
28 * rproc_elf_sanity_check() - Sanity Check ELF firmware image
29 * @rproc: the remote processor handle
30 * @fw: the ELF firmware image
31 *
32 * Make sure this fw image is sane.
33 */
34 int rproc_elf_sanity_check(struct rproc *rproc, const struct firmware *fw)
35 {
36 const char *name = rproc->firmware;
37 struct device *dev = &rproc->dev;
38 struct elf32_hdr *ehdr;
39 char class;
40
41 if (!fw) {
42 dev_err(dev, "failed to load %s\n", name);
43 return -EINVAL;
44 }
45
46 if (fw->size < sizeof(struct elf32_hdr)) {
47 dev_err(dev, "Image is too small\n");
48 return -EINVAL;
49 }
50
51 ehdr = (struct elf32_hdr *)fw->data;
52
53 /* We only support ELF32 at this point */
54 class = ehdr->e_ident[EI_CLASS];
55 if (class != ELFCLASS32) {
56 dev_err(dev, "Unsupported class: %d\n", class);
57 return -EINVAL;
58 }
59
60 /* We assume the firmware has the same endianness as the host */
61 # ifdef __LITTLE_ENDIAN
62 if (ehdr->e_ident[EI_DATA] != ELFDATA2LSB) {
63 # else /* BIG ENDIAN */
64 if (ehdr->e_ident[EI_DATA] != ELFDATA2MSB) {
65 # endif
66 dev_err(dev, "Unsupported firmware endianness\n");
67 return -EINVAL;
68 }
69
70 if (fw->size < ehdr->e_shoff + sizeof(struct elf32_shdr)) {
71 dev_err(dev, "Image is too small\n");
72 return -EINVAL;
73 }
74
75 if (memcmp(ehdr->e_ident, ELFMAG, SELFMAG)) {
76 dev_err(dev, "Image is corrupted (bad magic)\n");
77 return -EINVAL;
78 }
79
80 if (ehdr->e_phnum == 0) {
81 dev_err(dev, "No loadable segments\n");
82 return -EINVAL;
83 }
84
85 if (ehdr->e_phoff > fw->size) {
86 dev_err(dev, "Firmware size is too small\n");
87 return -EINVAL;
88 }
89
90 return 0;
91 }
92 EXPORT_SYMBOL(rproc_elf_sanity_check);
93
94 /**
95 * rproc_elf_get_boot_addr() - Get rproc's boot address.
96 * @rproc: the remote processor handle
97 * @fw: the ELF firmware image
98 *
99 * This function returns the entry point address of the ELF
100 * image.
101 *
102 * Note that the boot address is not a configurable property of all remote
103 * processors. Some will always boot at a specific hard-coded address.
104 */
105 u32 rproc_elf_get_boot_addr(struct rproc *rproc, const struct firmware *fw)
106 {
107 struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
108
109 return ehdr->e_entry;
110 }
111 EXPORT_SYMBOL(rproc_elf_get_boot_addr);
112
113 /**
114 * rproc_elf_load_segments() - load firmware segments to memory
115 * @rproc: remote processor which will be booted using these fw segments
116 * @fw: the ELF firmware image
117 *
118 * This function loads the firmware segments to memory, where the remote
119 * processor expects them.
120 *
121 * Some remote processors will expect their code and data to be placed
122 * in specific device addresses, and can't have them dynamically assigned.
123 *
124 * We currently support only those kind of remote processors, and expect
125 * the program header's paddr member to contain those addresses. We then go
126 * through the physically contiguous "carveout" memory regions which we
127 * allocated (and mapped) earlier on behalf of the remote processor,
128 * and "translate" device address to kernel addresses, so we can copy the
129 * segments where they are expected.
130 *
131 * Currently we only support remote processors that required carveout
132 * allocations and got them mapped onto their iommus. Some processors
133 * might be different: they might not have iommus, and would prefer to
134 * directly allocate memory for every segment/resource. This is not yet
135 * supported, though.
136 */
137 int rproc_elf_load_segments(struct rproc *rproc, const struct firmware *fw)
138 {
139 struct device *dev = &rproc->dev;
140 struct elf32_hdr *ehdr;
141 struct elf32_phdr *phdr;
142 int i, ret = 0;
143 const u8 *elf_data = fw->data;
144
145 ehdr = (struct elf32_hdr *)elf_data;
146 phdr = (struct elf32_phdr *)(elf_data + ehdr->e_phoff);
147
148 /* go through the available ELF segments */
149 for (i = 0; i < ehdr->e_phnum; i++, phdr++) {
150 u32 da = phdr->p_paddr;
151 u32 memsz = phdr->p_memsz;
152 u32 filesz = phdr->p_filesz;
153 u32 offset = phdr->p_offset;
154 void *ptr;
155
156 if (phdr->p_type != PT_LOAD)
157 continue;
158
159 dev_dbg(dev, "phdr: type %d da 0x%x memsz 0x%x filesz 0x%x\n",
160 phdr->p_type, da, memsz, filesz);
161
162 if (filesz > memsz) {
163 dev_err(dev, "bad phdr filesz 0x%x memsz 0x%x\n",
164 filesz, memsz);
165 ret = -EINVAL;
166 break;
167 }
168
169 if (offset + filesz > fw->size) {
170 dev_err(dev, "truncated fw: need 0x%x avail 0x%zx\n",
171 offset + filesz, fw->size);
172 ret = -EINVAL;
173 break;
174 }
175
176 /* grab the kernel address for this device address */
177 ptr = rproc_da_to_va(rproc, da, memsz);
178 if (!ptr) {
179 dev_err(dev, "bad phdr da 0x%x mem 0x%x\n", da, memsz);
180 ret = -EINVAL;
181 break;
182 }
183
184 /* put the segment where the remote processor expects it */
185 if (phdr->p_filesz)
186 memcpy(ptr, elf_data + phdr->p_offset, filesz);
187
188 /*
189 * Zero out remaining memory for this segment.
190 *
191 * This isn't strictly required since dma_alloc_coherent already
192 * did this for us. albeit harmless, we may consider removing
193 * this.
194 */
195 if (memsz > filesz)
196 memset(ptr + filesz, 0, memsz - filesz);
197 }
198
199 return ret;
200 }
201 EXPORT_SYMBOL(rproc_elf_load_segments);
202
203 static struct elf32_shdr *
204 find_table(struct device *dev, struct elf32_hdr *ehdr, size_t fw_size)
205 {
206 struct elf32_shdr *shdr;
207 int i;
208 const char *name_table;
209 struct resource_table *table = NULL;
210 const u8 *elf_data = (void *)ehdr;
211
212 /* look for the resource table and handle it */
213 shdr = (struct elf32_shdr *)(elf_data + ehdr->e_shoff);
214 name_table = elf_data + shdr[ehdr->e_shstrndx].sh_offset;
215
216 for (i = 0; i < ehdr->e_shnum; i++, shdr++) {
217 u32 size = shdr->sh_size;
218 u32 offset = shdr->sh_offset;
219
220 if (strcmp(name_table + shdr->sh_name, ".resource_table"))
221 continue;
222
223 table = (struct resource_table *)(elf_data + offset);
224
225 /* make sure we have the entire table */
226 if (offset + size > fw_size || offset + size < size) {
227 dev_err(dev, "resource table truncated\n");
228 return NULL;
229 }
230
231 /* make sure table has at least the header */
232 if (sizeof(struct resource_table) > size) {
233 dev_err(dev, "header-less resource table\n");
234 return NULL;
235 }
236
237 /* we don't support any version beyond the first */
238 if (table->ver != 1) {
239 dev_err(dev, "unsupported fw ver: %d\n", table->ver);
240 return NULL;
241 }
242
243 /* make sure reserved bytes are zeroes */
244 if (table->reserved[0] || table->reserved[1]) {
245 dev_err(dev, "non zero reserved bytes\n");
246 return NULL;
247 }
248
249 /* make sure the offsets array isn't truncated */
250 if (struct_size(table, offset, table->num) > size) {
251 dev_err(dev, "resource table incomplete\n");
252 return NULL;
253 }
254
255 return shdr;
256 }
257
258 return NULL;
259 }
260
261 /**
262 * rproc_elf_load_rsc_table() - load the resource table
263 * @rproc: the rproc handle
264 * @fw: the ELF firmware image
265 *
266 * This function finds the resource table inside the remote processor's
267 * firmware, load it into the @cached_table and update @table_ptr.
268 *
269 * Return: 0 on success, negative errno on failure.
270 */
271 int rproc_elf_load_rsc_table(struct rproc *rproc, const struct firmware *fw)
272 {
273 struct elf32_hdr *ehdr;
274 struct elf32_shdr *shdr;
275 struct device *dev = &rproc->dev;
276 struct resource_table *table = NULL;
277 const u8 *elf_data = fw->data;
278 size_t tablesz;
279
280 ehdr = (struct elf32_hdr *)elf_data;
281
282 shdr = find_table(dev, ehdr, fw->size);
283 if (!shdr)
284 return -EINVAL;
285
286 table = (struct resource_table *)(elf_data + shdr->sh_offset);
287 tablesz = shdr->sh_size;
288
289 /*
290 * Create a copy of the resource table. When a virtio device starts
291 * and calls vring_new_virtqueue() the address of the allocated vring
292 * will be stored in the cached_table. Before the device is started,
293 * cached_table will be copied into device memory.
294 */
295 rproc->cached_table = kmemdup(table, tablesz, GFP_KERNEL);
296 if (!rproc->cached_table)
297 return -ENOMEM;
298
299 rproc->table_ptr = rproc->cached_table;
300 rproc->table_sz = tablesz;
301
302 return 0;
303 }
304 EXPORT_SYMBOL(rproc_elf_load_rsc_table);
305
306 /**
307 * rproc_elf_find_loaded_rsc_table() - find the loaded resource table
308 * @rproc: the rproc handle
309 * @fw: the ELF firmware image
310 *
311 * This function finds the location of the loaded resource table. Don't
312 * call this function if the table wasn't loaded yet - it's a bug if you do.
313 *
314 * Returns the pointer to the resource table if it is found or NULL otherwise.
315 * If the table wasn't loaded yet the result is unspecified.
316 */
317 struct resource_table *rproc_elf_find_loaded_rsc_table(struct rproc *rproc,
318 const struct firmware *fw)
319 {
320 struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
321 struct elf32_shdr *shdr;
322
323 shdr = find_table(&rproc->dev, ehdr, fw->size);
324 if (!shdr)
325 return NULL;
326
327 return rproc_da_to_va(rproc, shdr->sh_addr, shdr->sh_size);
328 }
329 EXPORT_SYMBOL(rproc_elf_find_loaded_rsc_table);